1. Field of the Invention
The present invention relates to a soundproof panel, and in particular to a smart panel capable of decreasing a noise in a wide band frequency.
2. Description of the Background Art
Generally, a panel is formed of a board member (or a board structure) or a combined member of a board member and a sound absorption member or two kinds of board members and a sound absorption member. The above-described panel has an insertion loss decreased in a resonance frequency of the panel. As the use of a sound absorption is increased, an insertion loss is increased in an intermediate frequency and a high frequency band. An insertion loss of a panel having a double board member is increased compared to a panel of a single board member. The insertion loss may be decreased in a resonance frequency of a space formed by a board member and two board members.
Namely, the insertion loss of the panel may be increased in an intermediate/high frequency band by coupling an absorption member with a board member. In this case, it is impossible to prevent a decrease of an insertion loss in a resonance frequency of a panel.
In order to prevent the decrease of an insertion loss in a resonance frequency, there is a method in which a viscoelasticity member is attached to a board member. However, since the elastic member has a characteristic in which the viscoelasticity characteristic is decreased in a wide frequency region. Therefore, it is impossible to obtain a certain characteristic which is proper to a certain frequency. In addition, the weight of the board member is increased due to a viscoelasticity member attached for increasing the decreasing effect of the viscoelasticity characteristic. The increase of the mass may cause an additional driving force for a transfer mechanism for thereby decreasing the performance of the system.